In the United States alone, the market for solar PVs has grown by 800% from 2005 to 2012, with installed capacity rising from 4.5 GW to 65 GW. At this rate, it is expected that the cost of alternative generation of electricity could become equal to or cheaper than conventional generation in the near future. To reach this goal, known as grid parity, it is necessary to push the cost of PV systems down by 50-75%. Historically, the cost structure of solar PV systems was dominated by the cost of silicon cells. In 2012, given the significant decrease in cost of raw silica, the market has seen PV module prices dropping from $4.00 per Watt to $1.00 per Watt in 2012.
However, focusing efforts solely on efficient utilization of silicon is no longer a viable long-term strategy for maintaining the market growth rates. Module prices might be expected to decrease another 30%, but this alone will not drive the system cost to grid parity. Experts agree that the most significant contribution needs to come from a drastic reduction of the “balance of system cost.” Balance of System (“BoS”) costs are all costs associated with a PV system, except the cost of the PV modules and the inverters. They encompass all auxiliary components that allow the system to function, as well as labor costs and soft costs required to implement a solar system project. From the hardware side, BOS includes mounting and racking hardware, electrical wiring, interconnects, and monitoring equipment; labor costs include mounting, racking, and electrical labor; soft costs include permitting, inspection, grid tie hardware, overhead, and profit. Currently, BoS costs account for more than 40 percent of the total installed cost of solar energy systems.
In recognition of the potential of solar PVs to contribute to US energy independence and security goals, the United States Department of Energy (“DoE”) launched the SunShot initiative in 2010. The SunShot initiative aims to decrease the cost of solar energy by 75% by the end of the decade, to be achieved by reducing technology costs, grid integration costs, and accelerating solar deployment by reducing utility scale solar PV to $1 per Watt. Given the diffuse cost structure of solar PV systems, there is the need to recognize that no single component can accomplish alone the SunShot cost reduction objective. Instead, multiple cost drivers must be concurrently addressed, including material cost, manufacturing cost, business process, on site labor and equipment usage. This condition implies the need to identify new opportunities for systems integration that could eventually lead to more significant innovation in the field.
One strategy to deal with the complexity of BoS is a “divide and conquer” approach. This strategy entails the optimization of individual components and activities, launching isolated cost reduction efforts. A benefit of this approach is that it allows a high number of stakeholders to engage in relatively low complexity tasks. The downside is the high cost of maintaining compatibility standards between sub-systems, while missing the opportunity to achieve more innovative solutions through development of multifunctional components. Alternatively, a systems design approach revisits the requirements from the top down and focuses on fulfillment of system-level objectives. A characteristic of this approach is that it questions legacy solutions, shifting the focus towards opportunities to produce revolutionary results.
The DoE SunShot Initiative takes a pragmatic hybrid approach. Development of components and activities with low degrees of interdependence has been given low priority, while highly interdependent subsystems have been promoted and funded via systems design research projects. The Georgia Tech led SIMPLE BoS project is one such project that aims to reduce balance of system costs, a highly interdependent subsystem that has only recently been brought into the research domain. A key component of this interdependency is the need for better integration of PV systems with building systems, in a way that allows different aspects of building performance to remain uncompromised, and are eventually improved through PV system integration. The complexity inherent to the problem necessitates a multi-disciplinary approach and fuels the opportunity for transformational solutions.
Currently there are approximately 9,400 megawatts (“MW”) of solar power production in the United States. Utility-scale ground mount accounts for 1,200 MW with an additional 16,000 MW of utility-scale projects currently in development. Utility-scale is defined by the National Renewable Energy Laboratory as a five megawatt or larger PV installation and therefore requires a substantially different approach to installation as compared to smaller residential or commercial rooftop projects. The sheer scale of most ground mount PV power plants, which can exceed tens of thousands of modules, offers an opportunity to rethink the process of installation at each step in order to yield maximum economic benefits for the industry. As the solar capacity continues to grow, there continues to be a desire for improved mounting systems that increase structural integrity and decrease installation costs. Various embodiments of the present invention address these desires.